It Began with World War I

On April 30, 1916, at the height of World War I, clocks in the German Empire were set forward by 1 hour to start the world's first countrywide DST period.

Although a small town in Canada had experimented with seasonal clock changes as early as 1908, it was Germany's implementation that sparked a trend that soon spread across Europe. Within weeks, several countries had started using DST—among them the United Kingdom, France, Italy, Russia, and even Australia. The first DST clock change in the United States was in 1918.

However, the initial enthusiasm was short-lived in most countries. Germany stopped using DST in 1919 and Austria in 1921, while the United Kingdom, Ireland, and cities like Paris in France continued to set their clocks back and forth.

France Divided over DST

The French had mixed feelings about DST: The rural population didn't like it and got rid of it by 1920, but Paris and other major cities still favored it. In 1923, the French Cabinet decided that there would be no clock changes, but working hours would start and stop 30 minutes earlier between April 28 and November 3.

Germans Exported DST During World War II

During the Second World War, the practice of changing clocks again spread from Germany to many European countries. In fact, Hitler’s commanders imposed the measure on many of the countries they occupied—such as Denmark and Poland.

In the Netherlands, the Germans advanced local time by 1 hour and 40 minutes, effectively changing its time zone from “Dutch Time,” which was an approximation of solar time in Amsterdam, to Central European Summer Time (CEST). The Netherlands remained on year-round DST until 1942. From 1942 to 1945, Dutch clocks followed Germany's schedule of DST switches. After the country's liberation, DST was abolished, and there were no clock changes until 1977.

The French initially resisted DST, but by 1941, the country was officially changing its clocks. Some French patriots, however, stuck to the old French time, 2 hours behind the Berlin-based DST.

Discontinued after World War II

In some countries DST was still used in the immediate aftermath of World War II, mainly to conserve fuel for national recovery and rebuilding programs. The United Kingdom even implemented British Double Summer Time, which was 2 hours ahead of standard time, both during and after World War II.

However, many European countries later abandoned the measure as it became a reminder of the war itself. Italy, France, and many other countries repealed DST as soon as the debris of German occupation had been cleaned up.

Oil Shortage Brings DST Renaissance

It was another world crisis that led to the reintroduction of DST in most European countries. When the Organization of Arab Petroleum Exporting Countries (OAPEC) imposed an oil embargo in October 1973, energy prices skyrocketed, causing a recession across the continent—a situation that called for drastic measures. France was the first European country to revive DST in 1976. By the end of the 1970s, most of Europe was again changing its clocks twice a year.

In 1996, the European Union (EU) standardized the DST schedule. The directive is still in force today. Countries in the European Economic Area (EEA), except Iceland, start DST at 01:00 UTC on the last Sunday of March and turn their clocks back to standard time at 01:00 UTC on the last Sunday of October. Switzerland follows the same schedule although the country is not part of the EEA.